[chrisjsewell]

The package declares markdown-it-py>=2.0.0,<5.0.0, but that floor is not true:
with markdown-it-py 2.x, import mdit_py_plugins.subscript fails (ImportError: cannot import name 'EnvType').
This raises the floor to 3.0.0 and adds a CI job that tests it, so it stays true.

Changes

• pyproject.toml: markdown-it-py>=3.0.0,<5.0.0, and classifiers for Python 3.10 to 3.14
  (3.8 and 3.9 were already excluded by requires-python = ">=3.10").
• CI: a Python 3.14 cell in the tests matrix,
  and a tests-floor job that installs markdown-it-py==3.0.0 on Python 3.10 and runs the suite.
  It is a separate job rather than a matrix entry so that the existing tests (…) check names do not change;
  allgood and publish both need it.
• Tests: gfm, gfm_autolink and section_ref need markdown-it-py >= 4.1.0 and raise RuntimeError on older versions,
  so test_gfm.py, test_gfm_autolink.py and test_section_ref.py now skip below 4.1.0 (pytest.importorskip(..., minversion="4.1.0")).
  The version guards are tested in a new test_mdit_version_guard.py, which runs on every version:
  below 4.1.0 it checks that each of the three plugins raises its RuntimeError,
  and the existing simulated section_ref guard test moved there unchanged.
• pre-commit: mypy type-checks against markdown-it-py~=4.2 (was ~=3.0); no source changes were needed.
• tox: a py314 environment.

Checks run

• pytest on Python 3.14 with markdown-it-py 4.2.0: 728 passed, 3 skipped (the below-4.1 guard checks), 1 xfailed.
• pytest on Python 3.10 with markdown-it-py 3.0.0: 648 passed, 3 skipped (the three modules above), 1 xfailed.
  Removing the skip from test_section_ref.py makes 44 tests fail with the RuntimeError, so the skip is what keeps that job green.
• pre-commit run --all-files: clean.
• python -m build and twine check --strict: both distributions pass;
  the wheel's metadata says Requires-Dist: markdown-it-py>=3.0.0,<5.0.0.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.66%. Comparing base (d11bdaf) to head (9a5be73).
⚠️ Report is 36 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #170      +/-   ##
==========================================
+ Coverage   92.80%   94.66%   +1.86%     
==========================================
  Files          31       40       +9     
  Lines        1835     2325     +490     
==========================================
+ Hits         1703     2201     +498     
+ Misses        132      124       -8     

Flag	Coverage Δ
pytests	94.66% <ø> (+1.86%)	⬆️

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